Many users of mobile computing devices, such as smart phones, having telecommunications capabilities that enable communications with other users of other such devices using Short Message Service (SMS) messages. The SMS messages are routed through a mobile telecommunications network to an External Short Messaging Entity (ESME) which is a gateway or proxy device configured to route the messages using a Short Message Peer-to-Peer (SMPP) protocol to a Short Message Service Center (SMSC). In response to the binding or other ESME request messages, the SMSC sends one or more reply messages to the requesting ESME such as a binding response message, receipt acknowledgement, delivery confirmation, validity confirmation, or other response message, for example. Similarly, messages can be initiated by an SMSC and reply message can be sent by the ESME in response.
Since all messages are sent asynchronously according to the SMPP protocol, in order to accurately route reply messages, the initiating or requesting ESME or SMSC includes a sequence number in each request message. The responding ESME or SMSC retrieves the sequence number and inserts it into any message(s) sent in reply to the ESME or SMSC request message. However, SMSC bandwidth is often unable to effectively service SMPP messages, particularly during periods of high volume, resulting in some SMPP messages (and associated SMS messages) being dropped or significantly delayed, which is undesirable.